Methylation of FEN1 suppresses nearby phosphorylation and facilitates PCNA binding

Nat Chem Biol. 2010 Oct;6(10):766-73. doi: 10.1038/nchembio.422. Epub 2010 Aug 22.


Flap endonuclease 1 (FEN1), a structure-specific endo- and exonuclease, has multiple functions that determine essential biological processes, such as cell proliferation and cell death. As such, the enzyme must be precisely regulated to execute each of its functions with the right timing and in a specific subcellular location. Here we report that FEN1 is methylated at arginine residues, primarily at Arg192. The methylation suppresses FEN1 phosphorylation at Ser187. The methylated form, but not the phosphorylated form, of FEN1 strongly interacts with proliferating cell nuclear antigen (PCNA), ensuring the 'on' and 'off' timing of its reaction. Mutations of FEN1 disrupting arginine methylation and PCNA interaction result in unscheduled phosphorylation and a failure to localize to DNA replication or repair foci. This consequently leads to a defect in Okazaki fragment maturation, a delay in cell cycle progression, impairment of DNA repair and a high frequency of genome-wide mutations.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Arginine / chemistry
  • Arginine / metabolism
  • Binding Sites
  • DNA Damage
  • DNA Repair
  • DNA Replication
  • Flap Endonucleases / genetics
  • Flap Endonucleases / metabolism*
  • HeLa Cells
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Methylation
  • Phosphorylation
  • Proliferating Cell Nuclear Antigen / chemistry
  • Proliferating Cell Nuclear Antigen / metabolism*
  • Protein Binding
  • Protein Methyltransferases / metabolism
  • Protein-Arginine N-Methyltransferases
  • Reproducibility of Results


  • Proliferating Cell Nuclear Antigen
  • Arginine
  • Hydrogen Peroxide
  • Protein Methyltransferases
  • PRMT5 protein, human
  • Protein-Arginine N-Methyltransferases
  • Flap Endonucleases
  • FEN1 protein, human